On April 22nd, Earth Day, the U.S. Navy ran a test flight of an F/A-18 Green Hornet fighter on a 50-50 mixture of petroleum-based jet fuel and biofuel. The biofuel came from the camelina plant, a member of the mustard family. On hand to watch the flight was Secretary of the Navy Ray Mabus: “The Navy has always been in the leadership when we’ve changed energy sources. In the 1850s we went from sail to coal. In the early part of the 20th century we went from coal to oil.”

Mabus has committed the Navy to be an early adopter of alternative energy sources. He wants one of the 11 strike groups—an aircraft carrier and its support vessels—to be completely fossil-fuel free by 2016. That effort is as much based in national security as in environmental awareness. After the Green Hornet flight, Mabus said, “Not much of the fuel that we are using in the fleet today or using on our bases today comes from the U.S. We are too dependent on potentially volatile places on Earth for that energy.”